    [Patent document 1] JP-2008-183937 A    [Patent document 2] JP-2000-333305 A (U.S. Pat. No. 6,314,347)    [Patent document 3] JP-2001-183150 A    [Patent document 4] JP-2007-19687 A    [Patent document 5] JP-H11-195437 A    [Patent document 6] JP-2006-207539 A
There is conventionally known an in-vehicle battery for supplying an electric power to an electronic apparatus such as a motor in the vehicle while accumulating an electric power which the above motor generates by regeneration at the time of deceleration of the vehicle (for example, refer to Patent documents 1 to 6).
Such a battery deteriorates when a temperature becomes too high; thus, the battery temperature is monitored for preventing the deterioration. When the battery temperature becomes greater than the battery upper limit temperature, the battery restriction strengthening control is considered which reduces, in the battery, a maximum of the input and output power to another electronic apparatus.
There may be arising a situation where the battery restriction strengthening control is not executed in a road range enabling little energy accumulated by regeneration whereas the battery restriction strengthening control is executed in a road range (for example, downward slope) enabling much energy accumulated by regeneration. Such a situation makes it impossible to accumulate energy efficiently. The battery temperature has a general tendency to increase with increasing the regeneration. Thus, the above situation occurs often.